Guided by research on psychological safety, we used longitudinal survey data from a sample of 182 dual-earner male-female couples to examine the role of supportive coparenting in mediating relations between adult attachment orientations and parenting stress/satisfaction, and further considered whether parenting self-efficacy moderated relations between supportive coparenting and parenting stress/satisfaction. Path analyses using IBM SPSS AMOS 22 and bootstrapping techniques indicated that fathers' (but not mothers') perceptions of supportive coparenting at 3 months postpartum mediated the associations between their attachment anxiety in the third trimester of pregnancy and their parenting stress and satisfaction at 9 months postpartum. Additional tests of moderation revealed that mothers' perceptions of greater supportive coparenting were associated with lower parenting stress only when their parenting self-efficacy was low, but fathers' perceptions of greater supportive coparenting were associated with greater parenting satisfaction only when their parenting self-efficacy was high. Implications and limitations are discussed.